Pathetic service

I took a cellphone contract in August of which the agreed installment was R449.00 and month end September R563.00 was deducted and now issues because I knew with new contracts, first installment is usually higher. Now, I got statement stating amount due of R591.00 for this month. I've been calling and emailing with no success to get this resolved.. Finally today, a told they charged me insurance which I didn't agree to, immediately last month after receiving some policy documents I emailed them requesting t cancel that nonsense. I got cancelation email from them. Now, am being charged for something that is canceled and didn't agree to on the first place. Please advise me if is possible to cancel this and return your phone. I've been on hold for your insurance for 1 hour with no help except your consultants laughing at me in the background.